U.S. patent number 6,663,855 [Application Number 09/969,900] was granted by the patent office on 2003-12-16 for cosmetic and personal care compositions.
This patent grant is currently assigned to Unilever Home & Personal Care USA, division of Conopco, Inc.. Invention is credited to Jean M. J. Frechet, Damian Hajduk, Ezat Khoshdel, Mingjun Liu, Ralph B. Nielsen, Euan Stuart Reid, Keith Leslie Rutherford.
United States Patent |
6,663,855 |
Frechet , et al. |
December 16, 2003 |
Cosmetic and personal care compositions
Abstract
Cosmetic or personal care compositions, such as for styling
hair, comprise a thermoplastic elastomer which is a block copolymer
comprising a core polymer having a backbone comprising at least a
proportion of C--C bonds and two or more flanking polymers. Each
flanking polymer is covalently bound to an end of the core polymer
and the core polymer and/or at least one of the flanking polymers
is a copolymer derived from two or more monomers. The compositions
comprise a cosmetically acceptable diluent or carrier.
Inventors: |
Frechet; Jean M. J. (Oakland,
CA), Hajduk; Damian (San Jose, CA), Khoshdel; Ezat
(Wirral, GB), Liu; Mingjun (Santa Clara, CA),
Nielsen; Ralph B. (San Jose, CA), Reid; Euan Stuart
(Wirral, GB), Rutherford; Keith Leslie (Wirral,
GB) |
Assignee: |
Unilever Home & Personal Care
USA, division of Conopco, Inc. (Chicago, IL)
|
Family
ID: |
27447888 |
Appl.
No.: |
09/969,900 |
Filed: |
October 3, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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678085 |
Oct 3, 2000 |
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Foreign Application Priority Data
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Oct 3, 2000 [GB] |
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0024182 |
Nov 23, 2000 [GB] |
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0028604 |
Nov 23, 2000 [GB] |
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0028605 |
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Current U.S.
Class: |
424/70.11;
424/401; 424/47; 424/484; 424/486; 424/59; 424/60; 424/63;
424/70.1; 424/70.12; 424/70.15; 424/70.16; 424/70.17; 424/70.19;
424/70.21; 424/70.22; 424/70.27; 424/70.28; 514/772.4; 514/772.5;
514/772.6 |
Current CPC
Class: |
A61K
8/90 (20130101); A61Q 5/06 (20130101); A61K
2800/54 (20130101) |
Current International
Class: |
A61K
8/72 (20060101); A61K 8/90 (20060101); A61Q
5/06 (20060101); A61K 007/06 (); A61K 007/08 ();
A61K 007/075 (); A61K 007/42 (); A61K 047/32 () |
Field of
Search: |
;424/59,60,63,70.28,70.27,401,70.1,47,484,486,70.11,70.12,70.21,70.15,70.16
;514/772.4,77.5,772.6 |
References Cited
[Referenced By]
U.S. Patent Documents
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4988506 |
January 1991 |
Mitra et al. |
5019377 |
May 1991 |
Torgerson |
5271930 |
December 1993 |
Walele et al. |
5472686 |
December 1995 |
Tsubaki et al. |
5632998 |
May 1997 |
Midha et al. |
5660819 |
August 1997 |
Tsubaki et al. |
5700892 |
December 1997 |
Takiguchi et al. |
5965115 |
October 1999 |
Bolich, Jr. et al. |
5972356 |
October 1999 |
Peffly et al. |
5980878 |
November 1999 |
Torgerson et al. |
5986015 |
November 1999 |
Midha et al. |
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Foreign Patent Documents
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0320218 |
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Jun 1989 |
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EP |
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0412707 |
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Feb 1991 |
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EP |
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0408313 |
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Dec 1995 |
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EP |
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0728778 |
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Aug 1996 |
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EP |
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0412704 |
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Apr 1999 |
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EP |
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1043346 |
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Oct 2000 |
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EP |
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1425228 |
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Feb 1976 |
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GB |
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1425288 |
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Feb 1976 |
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GB |
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1512280 |
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May 1978 |
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GB |
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95/01383 |
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Jan 1995 |
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WO |
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95/01384 |
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Jan 1995 |
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WO |
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98/53794 |
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Dec 1998 |
|
WO |
|
Other References
JP 04091016A to Uchiyama et al. (3/92) assigned to Osaka Organic
Chem. Ind. Ltd. (English language Derwent Abstract, etc.). .
Search Report under section 17, Application No. GB 0024182.8 dated
Mar. 27, 2001..
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Primary Examiner: Page; Thurman K.
Assistant Examiner: Fubara; Blessing
Attorney, Agent or Firm: Aronson; Michael P.
Parent Case Text
This application is a continuation-in-part of U.S. patent
application Ser. No. 09/678,085 filed Oct. 3, 2000 now abandoned.
Claims
What is claimed is:
1. Cosmetic or personal care composition comprising a thermoplastic
elastomer which is a block copolymer comprising a core polymer
block comprised of monomers selected from acrylate esters, and two
or more flanking polymer blocks, each flanking polymer block being
covalently bound to an end of the core polymer block, wherein at
least one of the polymer blocks is a random copolymer derived from
two or more monomers; and a cosmetically acceptable diluent or
carrier.
2. Composition as claimed in claim 1, wherein the core polymer has
a Tg of from -100.degree. C. to 50.degree. C.
3. Composition as claimed in claim 1, wherein the flanking polymers
have a Tg of from 30.degree. C. to 150.degree. C.
4. Composition as claimed in claim 1, wherein the block copolymer
is linear or star-shaped.
5. Composition as claimed in claim 1, wherein the block copolymer
is a linear ABA block copolymer.
6. Composition as claimed in claim 5, wherein the block copolymer
has the structure (AB).sub.2 -Core, where A and B are polymeric
blocks and Core is a non-polymeric linking core.
7. Composition as claimed in claim 1, wherein the block copolymer
is soluble in a solvent selected from water, ethanol and mixtures
thereof.
8. Composition as claimed in claim 1, wherein at least one of the
monomers comprising the random copolymer block is hydrophilic and
at least one of the monomers comprising the random copolymer block
is hydrophobic.
9. Composition as claimed in claim 8 wherein the absolute
difference in log p values between the hydrophobic and hydrophilic
monomers is preferably at least about 0.5.
10. Composition as claimed in claim 1, wherein the core polymer is
a random copolymer of two or more different acrylate esters.
11. Composition as claimed in claim 1, wherein the core polymer is
a polymer or copolymer of a (C1-C3 alkoxy)C1-C6 alkyl acrylate.
12. Composition as claimed claim 11, wherein the core polymer is a
polymer or copolymer of (2-methoxyethyl) acrylate.
13. Composition as claimed in claim 1, wherein the flanking
polymers are random copolymers of an acrylamide with one or more
other vinylic monomers.
14. Composition as claimed in claim 1, wherein the flanking
polymers are polymers or copolymers of N,N-dimethyl acrylamide.
15. Composition as claimed in claim 1, which comprises from 0.1 to
10% by weight of the block copolymer.
16. Composition as claimed in claim 1, wherein the core polymer has
a weight average molecular weight of from 20 kDa to 500 kDa.
17. Composition as claimed in claim 1, wherein the flanking
polymers have a weight average molecular weight of from 200 Da to
50 kDa.
18. Composition as claimed in claim 1, wherein the molar ratio of
the core polymer to the flanking polymers is from 1:10 to 10:1.
19. Composition as claimed in claim 1, wherein the block copolymer
has a bond strength of at least 10 g at 40.degree. C. and 80%
relative humidity.
20. Composition as claimed in claim 1, wherein the block copolymer
has a bond strength of at least 15 g at 25.degree. C. and 80%
relative humidity.
21. Composition as claimed in claim 1, wherein the polymer has a
viscosity of less than 15 cp as determined for 5 wt % polymer in 50
vol % aqueous ethanol solution at 25.degree. C. using capillary
viscometry and assuming a viscosity for deionised water of 1
mPas.
22. Composition as claimed in claim 1, wherein the block copolymer
has a bond strength of at least 34 g at 25.degree. C. and 50%
relative humidity and an elastic modulus of less than 0.45 Gpa.
23. Composition as claimed in claim 1, which further comprises a
fragrance or perfume.
24. Composition as claimed in claim 1, which is a hairspray, mousse
or gel for styling hair.
25. Composition as claimed in claim 24, further comprising an
additional hair styling polymer.
26. Composition as claimed in claim 24, further comprising from
0.01% to 7.5% by weight of a surfactant.
27. Composition as claimed in claim 24, further comprising up to
30% by weight of a propellant.
28. Composition as claimed in claim 24 which is a hair styling
cream or gel including from 0.01% to 10% by weight of a structurant
or thickener.
29. A cosmetic method of treating hair which comprises the step of
applying to the hair a composition comprising a thermoplastic
elastomer which is a block copolymer comprising a core polymer
block comprised of monomers selected from acrylate esters; and two
or more flanking polymers blocks, each flanking polymer block being
covalently bound to an end of the core polymer block, wherein at
least one of the polymer blocks is a random copolymer derived from
two or more monomers; and a cosmetically acceptable diluent or
carrier.
30. Method as claimed in claim 29, wherein the hair is man hair.
Description
FIELD OF THE INVENTION
The present invention relates to cosmetic and personal care
compositions, such as hair styling compositions, containing block
copolymers, and to their use in the treatment of hair.
BACKGROUND AND PRIOR ART
Cosmetic and personal care compositions such as hair styling
sprays, mousses, gels, shampoos and conditioners, frequently
contain resins, gums and adhesive polymers to provide a variety of
benefits, for example, film-forming ability, thickening, sensory
properties and hair shaping and setting.
Polymers for use in such compositions are usually linear or graft
homo- or co-polymers which contain various monomers in an
alternating, random manner.
Graft copolymers are known for use as film-forming polymers in hair
care and other personal care compositions. These graft copolymers
typically comprise a polymeric backbone and one or more
macromonomers grafted to the backbone, in which the physical and
chemical attributes such as glass transition temperature and water
solubility can be selected independently for the polymeric backbone
and macromonomer grafts in order to provide the desired overall
polymer properties.
For example, WO95/01383 and WO95/01384 describe the use of water or
alcohol soluble or dispersible graft copolymers in hair and skin
care compositions, in which the copolymer has a backbone and two or
more polymeric side chains, and is formed by copolymerisation of
randomly repeating monomer units A and B. Monomer A is selected to
have a hydrophobic character and macromonomer B comprises a long
hydrophilic part. EP-A-0412704, EP-A-0408313 and EP-A-0412707 have
suggested the use of silicone grafted acrylate copolymers in hair
care applications. U.S. Pat. No. 4,988,506 describes the use of
non-pressure sensitive polysiloxane-grafted copolymers in hair care
compositions. U.S. Pat. No. 5,986,015 describes graft copolymers
and hair care compositions containing them.
Block copolymers have an advantage over graft copolymers in that
the polymer architecture can be controlled more readily. This is
particularly important when designing polymers with segments of
distinct physical and chemical properties for particular
applications. Graft copolymers typically have many side chains and
are not characterised as block copolymers.
WO 98/53794 discusses (AB).sub.n block copolymers, where A is a
silicone block and B is a vinylic block. U.S. Pat. No. 5,271,930
(Fintex Inc) describes benzoate esters of polyalkoxylated block
copolymers, such as PLURONICS.TM., for skin and hair care
compositions. U.S. Pat. Nos. 5,472,686 and 5,660,819 (both Nippon
Unicar) describe non-hydrolysing block copolymers comprising a
linear polysiloxane-polyoxyalkylene block as a repeating unit in
cosmetic formulations. U.S. Pat. Nos. 5,965,115 and 5,972,356 (both
Procter & Gamble) describe the use of silicone-polyoxyalkylene
copolymer surfactants for improving stability of a
polyorganosilicone emulsion in personal care compositions.
ABA triblock copolymers where the A blocks are hard and the B block
is soft, are generally referred to as "thermoplastic elastomers".
Such polymers are multiphase compositions in which the phases are
intimately dispersed. A well known material of this type is, for
example, poly(styrene-b-butadiene-b-styrene) commonly known as
Kraton.TM. and available from Shell Chemicals Company. However,
these materials are only soluble in common organic solvents such as
toluene and they are not soluble in cosmetically acceptable
solvents such as water and ethanol.
U.S. Pat. No. 5,980,878 discloses thermoplastic elastomers for use
in hair and skin care compositions which have a backbone polymer
and a plurality of polymeric side chains bound along the length of
the backbone polymer. The polymers described, which have a backbone
and a plurality of pendant polymer chains, are effectively graft
copolymers.
International applications numbers PCT/EP00/04225 and
PCT/EP00/04429 describe polysiloxane block copolymers which are
built up from units of the formula [A] and [B], in which A is a
polymeric block built up from radically polymerisable monomer and B
is a polysiloxane block. The block copolymers may be used in
cosmetic and personal care compositions.
GB 1425228 discloses hair spray or setting lotions containing ABA
block copolymers. The polymers are water insoluble and organic
solvents are required in the compositions in order to solubilise
the polymers. In all of the examples given, the A blocks are
poly(2-vinyl pyridine) and a typical B block is polybutadiene.
Furthermore, in all cases each of the A blocks and the B blocks is
derived from a single monomer ie, there is no copolymerisation
within the A or B blocks.
Compositions suitable for application to the hair containing
two-block or three-block copolymers are described in GB 1512280.
The polymers contain an A block which is a homopolymer obtained
from the polymerisation of an amino-substituted methacrylate ester,
optionally quaternised. Throughout the document, the A and B blocks
are taught as being obtained from a single monomer ie, the A and B
blocks are homopolymers.
It is an object of the present invention to provide cosmetic and
personal care compositions which exhibit advantages over the
compositions of the prior art. In particular, the invention aims to
provide a novel class of polymers for use in cosmetic and personal
care compositions. The invention involves compositions containing
polymers which can be produced relatively readily, and which have
properties that can be tailored to the particular application. The
hair treatment compositions of the invention which are useful for
styling hair may have advantages in terms of longer lasting hold
and/or improved feel.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a cosmetic or
personal care composition comprising a thermoplastic elastomer
which is a block copolymer comprising a core polymer having a
backbone comprising at least a proportion of C--C bonds and two or
more flanking polymers, each flanking polymer being covalently
bound to an end of the core polymer, wherein the core polymer
and/or at least one of the flanking polymers is a copolymer derived
from two or more monomers, and a cosmetically acceptable diluent or
carrier.
Further provided by the invention in a second aspect is a cosmetic
method of treating hair which comprises applying to the hair a
composition of the invention.
In a third aspect, the invention provides the use of a composition
of the invention for the cosmetic treatment of hair.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate, by way of example only,
preferred embodiments of the invention.
FIG. 1 is a plot showing SEC traces of an ABA copolymer after
polymerization of the midblock, and after addition of the endblocks
to the midblock.
FIG. 2 shows the in-phase (G') and out-of-phase (G") components of
the complex Theological modulus G* as a function of frequency
(.omega.) for a copolymer of DMA and MEA.
FIG. 3 shows the in-phase (E') and the out-of-phase (E") components
of the complex solid modulus E* for a copolymer of DMA, MEA, and
tert-butyl acrylate (tBA), which may be used in a composition of
the invention, as a function of temperature at a frequency of 10
Hz, a strain amplitude of 0.1%, and a heating rate of
2.5.degree.C./min.
DETAILED DESCRIPTION OF THE INVENTION
The present invention involves the development of polymers for use
in compositions for cosmetic and personal care applications. The
compositions comprise a thermoplastic elastomer. The thermoplastic
elastomer is a block copolymer comprising a core polymer having a
backbone comprising at least a proportion of C--C (ie,
carbon--carbon) bonds and two or more flanking polymers. The
linkages in the backbone of the core polymer preferably comprise
greater than 50%, more preferably greater than 75%, most preferably
greater then 95%, such as, for example, at least 99% (these
percentages being by number) C--C bonds. In some cases, the
backbone may contain 100% (by number) C--C bonds. Other bonds which
may be present in the backbone of the core polymer, in addition to
the C--C bonds, include, for example, C--O bonds. The flanking
polymers are bound to an end of the core polymer. Preferably, the
flanking polymers comprise at least a proportion of C--C (ie,
carbon--carbon) bonds. The linkages in the backbone of the flanking
polymer preferably comprise greater than 50%, more preferably
greater than 75%, most preferably greater then 95%, such as, for
example, at least 99% (these percentages being by number) C--C
bonds. In some cases, the backbone of the flanking polymer may
contain 100% (by number) C--C bonds. Other bonds which may be
present in the backbone of the flanking polymer, in addition to the
C--C bonds, include, for example, C--O bonds.
The core polymer can take a number of different forms. For example,
the core polymer may be linear or star-shaped (the latter polymers
also being termed "aerial"). Star-shaped polymers may have three or
more arms. When the core polymer is linear, a flanking polymer is
bound to each end of the core polymer and the resulting block
copolymer is an ABA block copolymer; this is a preferred embodiment
of the present invention. When the core polymer is star-shaped, a
flanking polymer is bound to each end of the core polymer and the
block copolymer therefore contains as many flanking polymers as
there are points or free ends in the star shaped polymer. For
example, if the star shaped core polymer has four ends the block
copolymer will comprise four flanking polymer groups.
Therefore, the block copolymer may have the structure (AB).sub.n
-Core, where A and B are polymeric blocks, n is 2 or more
(preferably 2, or 4, 6, 8 or 12) and Core is a non-polymeric
linking core. For ABA block copolymers, there may or may not be a
non-polymeric core in the B block, depending on how polymerisation
is carried out. Preferably, at least one of blocks A and B is a
random block comprising two or more monomers, wherein at least one
of the two or more monomers is hydrophilic and at least one of the
two or more monomers is hydrophobic; additionally, the absolute
difference in log p values between the hydrophobic and hydrophilic
monomers is preferably at least about 0.5. More preferably, the
flanking polymers are random copolymers.
Usually, the flanking polymer (such as component A in an ABA block
polymer) comprises or consists of a material that is hard at room
temperature (ie, it has a high Tg) but becomes soft and fluid upon
heating. Such materials are known in the art as "hard" blocks. The
core polymer (such as component B in an ABA block copolymer)
comprises or consists of a material that is soft at room
temperature (ie, it has a low Tg). Materials of this latter type
are known in the art as "soft blocks".
The glass transition temperature (Tg) of the flanking polymer (eg,
in the case of an ABA block copolymer, the A blocks) is typically
from 0 to 300.degree. C., preferably from 25 to 175.degree. C.,
more preferably from 30 to 150.degree. C. The glass transition
temperature of the core polymer (eg, in the case of an ABA block
copolymer, the B blocks) is typically from -200 to 150.degree. C.,
preferably from -100 to 75.degree. C., more preferably from -100 to
50.degree. C., most preferably from -75 to 50.degree. C. (such as
from -75 to less than 30.degree. C.). Those skilled in the art will
appreciate that the particular Tg values in any given case will
depend on the overall nature of the polymer and the identity of the
particular core and flanking polymers. The main requirement is that
the flanking polymers will constitute hard blocks, whilst the core
polymer will be a soft block. Typically, this means that the Tg of
the flanking polymers will be higher than that of the core
polymer.
Tg or glass transition is a well-known term in polymer science that
is used to describe the temperature at which a polymer or a segment
thereof undergoes a transition from a solid or brittle material to
a liquid or rubber-like material. The glass transition temperature
can be measured by a variety of standard techniques that are well
known in polymer science. A common technique for the determination
of glass transition temperature is differential scanning
calorimetry, commonly known as DSC. The glass transition phenomenon
in polymers is described in polymer textbooks and encyclopaedias,
for example "Principles of Polymer Chemistry", A Ravve, Plenum
Press, New York and London 1995, ISBN 0-306-44873-4.
The core and flanking polymer segments are generally
thermodynamically incompatible and they will therefore phase
separate into multiphase compositions in which the phases are
intimately dispersed.
The flanking and core polymers are typically selected in a manner
so as to produce a block copolymer with balanced
hydrophilic/hydrophobic character. The copolymer may be, for
example, soluble in water, ethanol or mixtures thereof or soluble
in other cosmetically acceptable diluents or carriers.
The copolymer is preferably soluble in a solvent selected from
water, ethanol and mixtures thereof. Preferably, the polymer is
soluble at a level of at least 0.1% by weight (more preferably at
least 1% by weight, eg, 1 to 25% by weight) in water, ethanol or a
water/ethanol mixture at 25.degree. C. By soluble, it is meant that
the polymer does not form a distinct separate phase (liquid or
solid) under the conditions specified.
The core polymer typically has a number average molecular weight of
from 100 to 10,000,000 Da (preferably from 2,000 to 200,000 Da,
more preferably from 10,000 to 100,000 Da) and a weight average
molecular weight of from 150 to 20,000,000 Da (preferably from
5,000 to 450,000 Da, more preferably from 20,000 to 400,000 Da).
The flanking polymers preferably have a number average molecular
weight of from 80 to 500,000 Da (preferably from 100 to 100,000 Da,
more preferably from 100 to 20,000 Da) and a weight average
molecular weight of from 80 to 700,000 Da (preferably from 100 to
250,000 Da, more preferably from 200 to 50,000 Da). The molar ratio
of the core polymer to the flanking polymers is typically from 1:10
to 10:1. Preferably, the molar ratio of the core polymer to the
flanking polymers is from 3:1 to 10:1.
The block copolymers of the invention preferably have elastic
moduli of from 1 to 1000 MPa, determined at 10 Hz, 1% strain,
25.degree. C. in a simple tension geometry after two days of
equilibration at 50% relative humidity, 25.degree. C.
The viscosity of the polymer is preferably less than 15 mPas
(centipoise; cp), more preferably less than 12 mPas, such as for
example in the range from 3 to 12 mPas (cp), as estimated for 5 wt
% polymer in 50 vol % aqueous ethanol solution at 25.degree. C.
using capillary viscometry and assuming a viscosity for deionised
water of 1 mPas. Polymers having this viscosity are particularly
useful in hair styling products which are formulated as sprays. For
use in other hair styling applications, the viscosity of the
polymers may be well outside this range.
Preferably, the block copolymers of the invention retain a
relatively high bond strength under conditions of relatively high
humidity. The polymers preferably have a bond strength of at least
10 g at 40.degree. C. and 80% relative humidity, the bond strength
being determined by the method described herein in the examples in
the section under the heading "Method for determining bond
strengths". More preferably, the polymers have a bond strength of
at least 15 g at 40.degree. C. and 80% relative humidity, even more
preferably a bond strength in the range of from 15 g to 30 g at
40.degree. C. and 80% relative humidity. The polymers most
preferably have a bond strength of at least 15 g at 25.degree. C.
and 80% relative humidity, such as, for example, a bond strength in
the range of from 15 g to 80 g (such as 15 g to 70 g eg, 25 g to 70
g) at 25.degree. C. and 80% relative humidity.
Preferably, the block copolymers of the invention have a bond
strength of at least 34 g at 25.degree. C. and 50% relative
humidity and an elastic modulus of less than 0.45 GPa. More
preferably, the polymer has a bond strength in the range of from 34
g to 100 g, more preferably from 34 g to 60 g at 25.degree. C. and
50% relative humidity.
The block copolymers also preferably have an elastic modulus of
less than 0.45 GPa, as determined by the method described herein in
the examples in the section under the heading "Method for
determining elastic modulus". Preferably, the polymer has an
elastic modulus in the range of from 0.01 to 0.45 GPa, more
preferably 0.05 to 0.45 GPa, most preferably 0.1 to 0.45 GPa.
The fact that the polymer retains a degree of bond strength at
relatively high temperatures and high humidity means that the
styling composition can continue to be effective at styling hair
under these conditions.
Preferably, the polymer consists essentially of (ie, contains at
least 95% and preferably substantially 100%) atoms selected from
carbon, hydrogen, oxygen and nitrogen.
It will be appreciated that the particular bond strength of the
polymer, which is most suitable for use in a composition of the
invention, will depend on the nature of the intended market for the
styling composition. The needs of the particular market will be
dictated by, for example, typical temperature and humidity
conditions in the geographical location defining that market
(regions of higher temperature and/or humidity requiring higher
bond strengths) and the preferences of local users of the
composition (which will be dictated by hair type and fashion and/or
cultural considerations). Thus, a variety of different polymers
having a variety of different bond strengths and other physical
properties are potentially useful in the compositions of the
invention. In order to achieve the desired bond strength and
humidity resistance and to balance this with the local requirements
of users of hair styling compositions, the chemical composition of
the polymers can be adjusted to optimise the balance of the desired
bond strength with other physical properties, such as glass
transition temperature and water solubility. For example, when the
polymer is a block copolymer, the composition of the flanking
polymers may be modified to include monomeric and/or polymeric
groups derived from monomers or comonomers, such as, for example,
N-isopropylacrylamide (NIPAM), methyl methacrylate (MMA),
tert-butyl acrylamide and mixtures thereof to provide blocks such
as, for example, methyl methacrylate-co-acrylic acid (MMA-co-AA).
Therefore, each of the flanking polymers may be a random copolymer
derived from at least one hydrophobic monomer and at least one
hydrophilic monomer.
Each of the core and flanking polymers may, independently, comprise
a combination of two or more monomers. Hence, the copolymers used
in the invention include, for example, ABA and ABC block
copolymers.
The flanking polymers in each thermoplastic elastomer molecule are
preferably substantially identical in terms of their composition
and molecular weight. However, the flanking polymers may,
alternatively, be different from each other in terms of their
composition and/or molecular weight.
Preferably, the flanking polymer and/or the core polymer, more
preferably both the core polymer and the flanking polymer, comprise
backbones which are obtainable by free radical polymerisation of
vinylic monomers. Suitable vinylic monomers include those based on
acrylate/methacrylate, acrylamide and/or styrenic systems. However,
other block copolymeric systems such as those derived by, for
example, addition polymerisation mechanisms such as
polycondensation can also be utilised, provided that the flanking
and core polymers are derived from hard and soft segments,
respectively.
The block copolymers of the present invention can be produced by
standard polymerisation techniques such as anionic or living free
radical polymerisation methodologies. Suitable methods for
preparing the polymers will be known to those skilled in the
art.
The core and flanking polymers may comprise different monomers or,
where each of the core and flanking polymers is a copolymer, may
have one or more monomers in common.
Free radically polymerisable monomers suitable for use in
polymerisation methods to produce polymers suitable for use in the
present invention are preferably ethylenically unsaturated
monomers. The living free radical polymerisation route is preferred
due to its versatility and commercial viability. By "polymerisable"
is preferably meant monomers that can be polymerised in accordance
with a living radical polymerisation.
By "ethylenically unsaturated" is meant monomers that contain at
least one polymerisable carbon--carbon double bond (which can be
mono-, di-, tri- or tetra-substituted). Either a single monomer or
a combination of two or more monomers can be utilised. In either
case, the monomers are selected to meet the physical and chemical
requirements of the final block copolymer.
Suitable ethylenically unsaturated monomers useful herein include
protected or non-protected acrylic acid and methacrylic acid and
salts, esters, anhydrides and amides thereof.
The acrylic acid and methacrylic acid salts can be derived from any
of the common non-toxic metal, ammonium, or substituted ammonium
counter ions.
The acrylic acid and methacrylic acid esters can be derived from
C.sub.1-40 straight chain, C.sub.3-40 branched chain, or C.sub.3-40
carbocyclic alcohols, from polyhydric alcohols having from about 2
to about 8 carbon atoms and from about 2 to about 8 hydroxyl groups
(non-limiting examples of which include ethylene glycol, propylene
glycol, butylene glycol, hexylene glycol, glycerin, and
1,2,6-hexanetriol); from amino alcohols (non-limiting examples of
which include aminoethanol, dimethylaminoethanol and
diethylaminoethanol and their quaternised derivatives); or from
alcohol ethers (non-limiting examples of which include
methoxyethanol and ethoxyethanol).
The acrylic acid and methacrylic acid amides can be unsubstituted,
N-alkyl or N-alkylamino mono-substituted, or N,N-dialkyl, or
N,N-dialkylamino disubstituted, wherein the alkyl or alkylamino
groups can be derived from C.sub.1-40 (preferably C.sub.1-10)
straight chain, C.sub.3-40 branched chain, or C.sub.3-40
carbocyclic moieties. In addition, the alkylamino groups can be
quaternised.
Also useful as monomers are protected and unprotected acrylic
or/and methacrylic acids, salts, esters and amides thereof, wherein
the substituents are on the two and/or three carbon position of the
acrylic and/or methacrylic acids, and are independently selected
from C.sub.1-4 alkyl, hydroxyl, halide (--Cl, --Br, --F, --I),
--CN, and --CO.sub.2 H, for example methacrylic acid, ethacrylic
acid, alpha-chloroacrylic acid and 3-cyano acrylic acid. The salts,
esters, and amides of these substituted acrylic and methacrylic
acids can be defined as described above for the acrylic/methacrylic
acid salts, esters and amides.
Other useful monomers include vinyl and allyl esters of C.sub.1-40
straight chain, C.sub.3-40 branched chain, or C.sub.3-40
carbocyclic carboxylic acids, vinyl and allyl halides (eg, vinyl
chloride, allyl chloride), (eg, vinyl pyridine, allyl pyridine);
vinylidene chloride; and hydrocarbons having at least one
unsaturated carbon--carbon double bond (eg, styrene,
alpha-methylstyrene, t-butylstyrene, butadiene, isoprene,
cyclohexadiene, ethylene, propylene, 1-butene, 2-butene,
isobutylene, p-methylstyrene); and mixtures thereof.
Preferred ethylenically unsaturated monomers have the following
general formula:
in which R.sup.1 and R.sup.2 are independently selected from
hydrogen, C.sub.1 -C.sub.10 straight or branched chain alkyl (the
term alkyl, when used herein, refers to straight chain and branched
groups), methoxy, ethoxy, 2-hydroxyethoxy, 2-methoxyethyl and
2-ethoxyethyl groups; G is selected from hydroxyl, --O(M).sub.1/v,
--OR.sup.3, --NH.sub.2, --NHR.sup.3 and --N(R.sup.3)(R.sup.4);
where M is a counter-ion of valency v selected from metal ions such
as alkali metal ions and alkaline earth metal ions, ammonium ions
and substituted ammonium ions such as mono-, di-, tri- and
tetraalkylammonium ions, and each R.sup.3 and R.sup.4 is
independently selected from hydrogen, C.sub.1 -C.sub.8 straight or
branched chain alkyl, N,N-dimethylaminoethyl, 2-hydroxyethyl,
2-methoxyethyl, and 2-ethoxyethyl.
More preferred specific monomers useful herein include those
selected from protected and unprotected acrylic acid, methacrylic
acid, ethacrylic acid, methyl acrylate, ethyl acrylate,
.alpha.-butyl acrylate, iso-butyl acrylate, t-butyl acrylate,
2-ethylhexyl acrylate, decyl acrylate, octyl acrylate, methyl
methacrylate, ethyl methacrylate, n-butyl methacrylate, iso-butyl
methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate,
decyl methacrylate, methyl ethacrylate, ethyl ethacrylate, n-butyl
ethacrylate, iso-butyl ethacrylate, t-butyl ethacrylate,
2-ethylhexyl ethacrylate, decyl ethacrylate, 2,3-dihydroxypropyl
acrylate, 2,3-dihydroxypropyl methacrylate, 2-hydroxyethyl
acrylate, 2-hydroxypropyl acrylate, hydroxypropyl methacrylate,
glyceryl monoacrylate, glyceryl monoethacrylate, glycidyl
methacrylate, glycidyl acrylate, acrylamide, methacrylamide,
ethacrylamide, N-methyl acrylamide, N,N-dimethyl acrylamide,
N,N-dimethyl methacrylamide, N-ethyl acrylamide, N-isopropyl
acrylamide, N-butyl acrylamide, N-t-butyl acrylamide,
N,N-di-n-butyl acrylamide, N,N-diethylacrylamide, N-octyl
acrylamide, N-octadecyl acrylamide, N,N-diethylacrylamide, N-phenyl
acrylamide, N-methyl methacrylamide, N-ethyl methacrylamide,
N-dodecyl methacrylamide, N,N-dimethylaminoethyl acrylamide,
quaternised N,N-dimethylaminoethyl acrylamide,
N,N-dimethylaminoethyl methacrylamide, quaternised
N,N-dimethylaminoethyl methacrylamide, N,N-dimethylaminoethyl
acrylate, N,N-dimethylaminoethyl methacrylate, quaternised
N,N-dimethyl-aminoethyl acrylate, quaternised
N,N-dimethylaminoethyl methacrylate, 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate, 2-hydroxyethyl ethacrylate, glyceryl
acrylate, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate,
2-methoxyethyl ethacrylate, 2-ethoxyethyl acrylate, 2-ethoxyethyl
methacrylate, 2-ethoxyethyl ethacrylate, maleic acid, maleic
anhydride and its half esters, fumaric acid, itaconic acid,
itaconic anhydride and its half esters, crotonic acid, angelic
acid, diallyldimethyl ammonium chloride, vinyl pyrrolidone vinyl
imidazole, methyl vinyl ether, methyl vinyl ketone, maleimide,
vinyl pyridine, vinyl pyridine-N-oxide, vinyl furan, styrene
sulphonic acid and its salts, allyl alcohol, allyl citrate, allyl
tartrate, vinyl acetate, vinyl alcohol, vinyl caprolactam, vinyl
acetamide, vinyl formamide and mixtures thereof.
Even more preferred monomers are those selected from methyl
acrylate, methyl methacrylate, methyl ethacrylate, ethyl acrylate,
ethyl methacrylate, ethyl ethacrylate, n-butyl acrylate, n-butyl
methacrylate, n-butyl ethacrylate, 2-ethylhexyl acrylate,
2-ethylhexyl methacrylate, 2-ethylhexyl ethacrylate, N-octyl
acrylamide, 2-methoxyethyl acrylate, 2-hydroxyethyl acrylate,
N,N-dimethylaminoethyl acrylate, N,N-dimethylaminoethyl
methacrylate, acrylic acid, methacrylic acid, N-t-butylacrylamide,
N-sec-butylacrylamide, N,N-dimethylacrylamide,
N,N-dibutylacrylamide, N,N-dihydroxyethyllacrylamide 2-hydroxyethyl
acrylate, 2-hydroxyethyl methacrylate, benzyl acrylate,
4-butoxycarbonylphenyl acrylate, butyl acrylate, 4-cyanobutyl
acrylate, cyclohexyl acrylate, dodecyl acrylate, 2-ethylhexyl
acrylate, heptyl acrylate, iso-butyl acrylate, 3-methoxybutyl
acrylate, 3-methoxypropyl acrylate, methyl acrylate, N-butyl
acrylamide, N,N-dibutyl acrylamide, ethyl acrylate, methoxyethyl
acrylate, hydroxyethyl acrylate, diethyleneglycolethyl acrylate and
mixtures thereof.
Particularly preferred for the flanking polymers are polymers or
copolymers of an acrylamide eg, N,N-dialkylacrylamides, preferably
N,N-dimethylacrylamide Copolymers include, for example, random
copolymers of an acrylamide with one or more other vinylic monomers
eg, another acrylamide or an acrylate ester, as described
hereinbefore. Representative examples of particularly preferred
monomers for the flanking polymers therefore include, but are not
restricted to: acrylamide, methacrylamide, N-tert-butylacrylamide,
N-sec-butylacrylamide, N,N-dimethylacrylamide,
N,N-dibutylacrylamide, N,N-dihydroxyethylacrylamide, acrylic and
methacrylic acids and their sodium, potassium, ammonium salts,
styrene, styrenesulphonic acid, N,N-dialkylaminoethyl acrylate,
N,N-dialkylaminoethyl acrylamide, vinylformamide, tert-butyl
acrylate, tert-butyl methacrylate, and, where the flanking polymer
is a copolymer, mixtures thereof. N,N-dialkylacrylamides and
N-alkylacrylamides, wherein the alkyl groups are C.sub.1 -C.sub.8
straight or branched chain alkyl (particularly
N,N-dimethylacrylamide), are the most preferred class of monomers
for the flanking polymer, and are preferably used as copolymers
with C1-C6 alkyl acrylate or methacrylate esters (such as methyl
methacrylate) or acrylic acid when one or both of the flanking
polymers is a copolymer.
It is preferred that the core polymer is a polymer or copolymer of
an acrylate ester. Copolymers may, for example, be random
copolymers of two or more (preferably two) different acrylate
esters. Preferred acrylate esters are esters of acrylic acid and
C.sub.1 -C.sub.8 straight or branched chain alcohols.
Representative examples of monomers for the core polymer include,
but are not restricted to: benzyl acrylate, 4-butoxycarbonylphenyl
acrylate, butyl acrylate, 4-cyanobutyl acrylate, cyclohexyl
acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, heptyl acrylate,
iso-butyl acrylate, 3-methoxybutyl acrylate, 3-methoxypropyl
acrylate, methyl acrylate, neopentyl acrylate, nonyl acrylate,
octyl acrylate, phenethyl acrylate, propyl acrylate, N-butyl
acrylamide, N,N-dibutyl acrylamide, ethyl acrylate, methoxyethyl
acrylate, hydroxyethyl acrylate, diethyleneglycolethyl acrylate.
More preferred are polymers or copolymers of a (C1-C3 alkoxy)C1-C6
alkyl acrylate. Particularly preferred core polymers are polymers
or copolymers of (2-methoxyethyl) acrylate. The copolymers may be
copolymers of (2-methoxyethyl) acrylate with C.sub.1 to C.sub.6
alkyl acrylate esters such as, for example, t-butyl acrylate.
In one embodiment of the invention, preferred polymers are ABA
block copolymers in which the A blocks are
poly(N,N-dimethylacrylamide) or
poly(N,N-dimethylacrylamide-co-methyl methacrylate) and the B block
is poly-((2-methoxyethyl) acrylate) or poly((2-methoxyethyl)
acrylate-co-tert butyl acrylate). Even more preferred are ABA block
copolymers in which the A blocks are
poly(N,N-dimethylacrylamide-co-methyl methacrylate) and the B block
is poly-((2-methoxyethyl) acrylate) and ABA block copolymers in
which the A blocks are poly(N,N-dimethylacrylamide) and the B block
is poly((2-methoxyethyl) acrylate-co-tert butyl acrylate).
The block copolymers of the invention may have further polymer
chains grafted onto the core polymer and/or one or more (or all) of
the flanking polymers. Suitable polymer chains for grafting onto
the block copolymers include, for example, silicones, and polymers
derived from monomers such as acrylate and methacrylate esters (eg,
esters of acrylic or methacrylic acid with C.sub.1 -C.sub.8
straight or branched chain alcohols), styrene (optionally
substituted with one or more C.sub.1 -C.sub.12 straight or branched
chain alkyl groups) and mixtures thereof. Other suitable polymer
chains include polyalkyleneglycols, such as polyethyleneglycol or
polypropyleneglycol. The polymer chains which may be grafted onto
the block copolymers may be hydrophobic or hydrophilic and
hydrophobic, hydrophilic or mixtures of hydrophobic and hydrophilic
chains may be grafted onto the block copolymers. Suitable
hydrophobic and hydrophilic macromers for the grafts are described
in WO 95/06078.
ABA Block Copolymers
The preferred polymers for use in the present invention are ABA
block copolymers. As used herein, "A-B-A block copolymer" refers to
a polymer comprising at least three segments having at least two
differing compositions and also having any one of a number of
different architectures, where the monomers are not incorporated
into the polymer architecture in a solely statistical or
uncontrolled manner. The transition from each A block to B block
may be sharply defined or may be tapered (ie, there may be a
gradual compositional change from A to B blocks). Although there
may be two, three, four or more monomers in a single block-type
polymer architecture, it will still be referred to herein as a
block copolymer. In some embodiments, the block copolymers of this
invention include one or more blocks of random copolymer (referred
to herein as an "R" block) together with one or more blocks of
single monomers. Thus, the polymer architecture may be A-R-A,
R-B-R, R-B-A, R-R'-R, A-R-B-A or A-R-B-R-A, where R and R' are
random blocks of monomers A and B or of monomers B and C or more
monomers. Moreover, the random block can vary in composition or
size with respect to the overall block copolymer. In some
embodiments, for example, the random block will account for between
5 and 80% by weight of the mass of the block copolymer. In other
embodiments, the random block R will account for more or less of
the mass of the block copolymer, depending on the application.
Furthermore, the random block may have a compositional gradient of
one monomer to the other (e.g., A:B) that varies across the random
block in an algorithmic fashion, with such algorithm being either
linear having a desired slope, exponential having a desired
exponent (such as a number from 0.1-5) or logarithmic. The random
block may be subject to the same kinetic effects, such as
composition drift, that would be present in any other radical
copolymerization and its composition, and size may be affected by
such kinetics, such as Markov kinetics. Any of the monomers listed
elsewhere in this specification may be used in the block copolymers
of this invention.
A "block" within the scope of the block copolymers of this
invention typically comprises about 5 or more monomers of a single
type (with the random blocks being defined by composition and/or
weight percent, as described above). In preferred embodiments, the
number of monomers within a single block may be about 10 or more,
about 15 or more, about 20 or more or about 50 or more. Each block
may have a desired architecture and thus, each block may be linear,
branched (with short or long chain branches), star (with 3 or more
arms), etc. Other architectures will be apparent to those of skill
in the art upon review of this specification.
In one embodiment, block copolymers are assembled by the sequential
addition of different monomers or monomer mixtures to living
polymerization reactions. In another embodiment, the addition of a
pre-assembled functionalized block (such as a telechelic oligomer
or polymer) to a free radical polymerization mixture yields a block
copolymer (e.g., the polymerization mixture may be controlled or
"living"). Ideally, the growth of each block occurs with high
conversion. Conversions are determined by NMR via integration of
polymer to monomer signals. Conversions may also be determined by
size exclusion chromatography (SEC) via integration of polymer to
monomer peak. For UV detection, the polymer response factor must be
determined for each polymer/monomer polymerization mixture. Typical
conversions can be 50% to 100% for each block, more specifically in
the range of from about 60% to about 90%). Intermediate conversion
can lead to block copolymers with a random copolymer block
separating the two or more homopolymer blocks, depending on the
relative rates of polymerization and monomer addition. At high
conversion, the size of this random block is sufficiently small
such that it is less likely to affect polymer properties such as
phase separation, thermal behaviour and mechanical modulus. This
fact can be intentionally exploited to improve polymerization times
for many applications without measurably affecting the performance
characteristics of the resulting polymer. This is achieved by
intentionally "killing" or terminating the living nature of the
polymerization when a desired level of conversion (e.g., >80%)
is reached by, e.g., cooling the polymerization to room temperature
or by neutralizing the control agent, for example by introducing
acids, bases, oxidizing agents, reducing agents, radical sources,
scavengers, etc. In the absence of a radical control agent, the
polymerization continues uncontrolled (typically at much higher
reaction rates) until the remaining monomer is consumed.
The existence of a block copolymer according to this invention is
determined by methods known to those of skill in the art. For
example, those of skill in the art may consider nuclear magnetic
resonance (NMR) studies of the block copolymer. Those of skill in
the art would also consider the measured increase of molecular
weight upon addition of a second monomer to chain-extend a living
polymerization of a first monomer. Block copolymer structure can be
suggested by observation microphase separation, including long
range order (determined by X-ray diffraction), microscopy and/or
birefringence measurements. Other methods of determining the
presence of a block copolymer include mechanical property
measurements, (e.g., elasticity of soft/hard/soft block
copolymers), thermal analysis and chromatography (e.g., absence of
homopolymer).
Measurement of optical properties, such as absorbance (color and
clarity), provides information about the phase morphology and
microstructure of the polymer emulsions. Thus, for example,
birefringence measurements may indicate the presence of optical
anisotropy resulting from microphase separation in hard/soft block
copolymers. Likewise, sharp color delineations in optical
micrographs of annealed polymer films can indicate the presence of
ordered, microphase-separated block copolymer structure.
Block copolymers of sufficiently high molecular weight phase
separate on a microscopic scale, to form periodically arranged
microdomains which typically comprise predominantly one or the
other polymer. These may take the form of lamellae, cylinders,
spheres, and other more complex morphologies, and the domain sizes
and periods are typically in the range 10-100 nm. Such microphase
separation can be detected obtained in a variety of ways, including
electron microscopy, x-ray or neutron scattering or reflectivity,
measurement of optical anisotropy, and rheological measurements.
The absence of a periodic microstructure is not necessarily
evidence against having synthesized a block copolymer, as such
absence may be due to low molecular weight, broad molecular weight
distribution of the individual blocks, weak intermolecular
interactions, or inadequate time and slow kinetics for microphase
separation. However, the presence of a periodic microstructure on
the 10-100 nm scale is considered extremely compelling evidence for
block copolymer formation in accord with this invention. A periodic
microstructure is not, however, an essential feature of the
copolymers which may be used in the compositions of this
invention.
Block copolymers are well-known to form terraced films, where the
film thickness is restricted to integer or half-integer multiples
of the microstructure period. This occurs because preferential
interactions of one or the other block with the substrate and/or
free surface cause a layering of the microdomains parallel to the
film surface (see for example G. Coulon, D. Ausserre, and T. P.
Russell, J. Phys. (Paris) 51, 777 (1990); and T. P. Russell, G.
Coulon, V. R. Deline, and D. C. Miller, Macromolecules 22, 4600-6
(1989)). When observed in a reflection microscope (on a reflecting
substrate such as a silicon wafer), the terracing manifests itself
as a series of discrete, well-defined colors with sharp boundaries
between them. The colors are a result of interference between light
reflected from the top and bottom surfaces of the film, and depend
on the local film thickness ("Newton's rings"). If terracing does
not occur, the colors blend continuously from one into the
other.
The presence of chemically homogeneous sequences within block
copolymers leads to a phase transition known as microphase
separation. Energetically unfavorable interactions between
chemically distinct monomers drive the blocks to separate into
spatially distinct domains. Since the blocks are covalently bound
together, these domains are comparable in size to the dimensions of
the polymers themselves. The presence of these domains alters the
physical properties of the materials, giving the resulting
composite many of the chemical and physical characteristics of each
block.
Polymerisation Process
Although any conventional method can be used for the synthesis of
the block copolymers of the invention, living free radical
polymerisation is the preferred polymerisation process. Such
polymerisations are described in the literature, for example:
Tailored polymers by free radical processes, E Rizzardo et al,
Macromol. Symp. 1999, 143 (World Polymer Congress, 37.sup.th
International Symposium on Macromolecules, 1998), 291-307, ISSN:
102-1360: also Atom transfer radical polymerisation and controlled
radical polymerisation, Z Zhang, et al, Gaofenzi Tongabo, 1999, (3)
138-144; K Matyjazewski, Classification and comparison of various
controlled/"living" radical polymerisations, Book of Abstracts,
218.sup.th ACS National Meeting, New Orleans, Aug. 22-26 (1999),
Poly-042.
In principle, any "living" free radical polymerisation techniques
such as nitroxide radical controlled, atom transfer radical
polymerisation (ATRP), reversible addition fragmentation chain
transfer (RAFT) and catalytic chain transfer (CCT) could be used.
The preferred polymerisation routes for the block copolymers of
this invention are nitroxide mediated processes. Thus, a
bis-nitroxide initiator may be employed to produce well-defined ABA
block copolymers. The process comprises two steps. In the first
step, a core polymer of a defined length is synthesised with the
bis-nitroxide initiator at the "centre" of the core polymer. This
involves the living polymerisation of the monomer or monomers with
a bis-nitroxide initiator. After this first stage is complete, the
core polymer is optionally purified or used without purification.
The second step involves the introduction of the flanking polymer
monomer or monomers using the same technique of living
polymerisation. The polymerisation process can be closely monitored
by gel permeation chromatography (GPC), NMR and viscosity
measurements. The polymerisation process is preferably stopped when
high conversions are achieved.
Living free radical polymerization techniques suitable for use in
the preparation of polymers for use in the invention include, for
example, those described in Hawker et al., "Development of a
Universal Alkoxyamine for `Living` Free Radical Polymerizations,"
J. Am. Chem. Soc., 1999, 121(16), pp. 3904-3920 for a nitroxide
mediated processes and in U.S. patent application Ser. No.
09/520,583, filed Mar. 8, 2000 and corresponding international
application PCT/US00/06176, which process is particularly
preferred, and both of these applications are incorporated herein
by reference.
Suitable polymerisation reactions include, for example, the
following ratios of starting materials, temperature, pressure,
atmosphere and reaction time. Temperatures for polymerization are
typically in the range of from about 80.degree. C. to about
130.degree. C., more preferably in the range of from about
95.degree. C. to about 130.degree. C. and even more preferably in
the range of from about 120.degree. C. to about 130.degree. C. The
atmosphere may be controlled, with an inert atmosphere being
preferred, such as nitrogen or argon. The molecular weight of the
polymer can be controlled via controlled free radical
polymerization techniques or by controlling the ratio of monomer to
initiator. Generally, the ratio of monomer to initiator is in the
range of from about 200 to about 800. In a nitroxide radical
controlled polymerization the ratio of control agent to initiator
can be in the range of from about 1 mol % to about 10 mol % and
this is preferred. The polymerization may be carried out in bulk or
in a suitable solvent such as diglyme. Polymerization reaction time
may be in the range of from about 0.5 hours to about 72 hours,
preferably from about 1 hour to about 24 hours and more preferably
from about 2 hours to about 12 hours.
The polymers used in the present invention are preferably produced
by the living free radical process.
Compositions of the Invention
Compositions of the present invention are preferably formulated
into hair care compositions, especially hairspray compositions, but
can also be formulated into a wide variety of product types,
including mousses, gels, lotions, tonics, sprays, shampoos,
conditioners, rinses, hand and body lotions, facial moisturisers,
sunscreens, anti-acne preparations, topical analgesics, mascaras,
and the like. Compositions of the invention comprise a cosmetically
acceptable diluent or carrier. Preferably, the compositions are for
use in styling human hair and, more preferably, they are packaged
and labelled as such.
Compositions of the invention preferably contain the polymer in an
amount of from 0.01% to 30% (more preferably from 0.1 to 10%, even
more preferably from 0.1 to 5%) by weight. Compositions of the
invention may, optionally, comprise a fragrance or perfume and/or
one or more of the optional additional components described
hereinafter.
The carriers and additional components required to formulate such
products vary with product type and can be routinely chosen by one
skilled in the art. The following is a description of some of these
carriers and additional components.
Carriers
Hair care compositions of the present invention can comprise a
carrier, or a mixture of such carriers, which are suitable for
application to the hair. The carriers are present at from about
0.5% to about 99.5%, preferably from about 5.0% to about 99.5%,
more preferably from about 10.0% to about 98.0%, of the
composition. As used herein, the phrase "suitable for application
to hair" means that the carrier does not damage or negatively
affect the aesthetics of hair or cause irritation to the underlying
skin.
Carriers suitable for use with hair care compositions of the
present invention include, for example, those used in the
formulation of hair sprays, mousses, tonics, gels, shampoos,
conditioners, and rinses. The choice of appropriate carrier will
also depend on the particular thermoplastic elastomer to be used,
and whether the product formulated is meant to be left on the
surface to which it is applied (e.g., hair spray, mousse, tonic, or
gel) or rinsed off after use (e.g., shampoo, conditioner,
rinse).
The carriers used herein can include a wide range of components
conventionally used in hair care compositions. The carriers can
contain a solvent to dissolve or disperse the particular
thermoplastic elastomer being used, with water, the C.sub.1
-C.sub.6 alcohols, lower alkyl acetate and mixtures thereof being
preferred. The carriers can also contain a wide variety of
additional materials such as acetone, hydrocarbons (such as
isobutane, hexane, decene), halogenated hydrocarbons (such as
Freons) and volatile silicones such as cyclomethicone.
When the hair care composition is a hair spray, tonic, gel, or
mousse the preferred solvents include water, ethanol, volatile
silicone derivatives, and mixtures thereof. The solvents used in
such mixtures may be miscible or immiscible with each other.
Mousses and aerosol hair sprays can also utilise any of the
conventional propellants to deliver the material as a foam (in the
case of a mousse) or as a fine, uniform spray (in the case of an
aerosol hair spray). Examples of suitable propellants include
materials such as trichlorofluoromethane, dichlorodifluoromethane,
difluoroethane, dimethylether, propane, n-butane or isobutane. A
tonic or hair spray product having a low viscosity may also utilise
an emulsifying agent. Examples of suitable emulsifying agents
include nonionic, cationic, anionic surfactants, or mixtures
thereof. If such an emulsifying agent is used, it is preferably
present at a level of from about 0.01% to about 7.5% by weight
based on total weight of the composition. The level of propellant
can be adjusted as desired but is generally from about 3% to about
30% by weight based on total weight for mousse compositions and
from about 15% to about 50% by weight based on total weight for
aerosol hair spray compositions.
Suitable spray containers are well known in the art and include
conventional, non-aerosol pump sprays i.e., "atomisers", aerosol
containers or cans having propellant, as described above, and also
pump aerosol containers utilising compressed air as the
propellant.
Where the hair care compositions are conditioners and rinses, the
carrier can include a wide variety of conditioning materials. Where
the hair care compositions are shampoos, the carrier can include,
for example, surfactants, suspending agents, and thickeners. Hair
styling creams or gels also typically contain a structurant or
thickener, typically in an amount of from 0.01% to 10% by
weight.
The carrier can be in a wide variety of forms. For example,
emulsion carriers, including oil-in-water, water-in-oil,
water-in-oil-in-water, and oil-in-water-in-silicone emulsions, are
useful herein. These emulsions can cover a broad range of
viscosities, e.g., from about 100 cps to about 200,000 cps. These
emulsions can also be delivered in the form of sprays using either
mechanical pump containers or pressurised aerosol containers using
conventional propellants. These carriers can also be delivered in
the form of a mousse. Other suitable topical carriers include
anhydrous liquid solvents such as oils, alcohols, and silicones
(e.g., mineral oil, ethanol, isopropanol, dimethicone,
cyclomethicone, and the like); aqueous-based single phase liquid
solvents (e.g., hydro-alcoholic solvent systems); and thickened
versions of these anhydrous and aqueous-based single phase solvents
(e.g., where the viscosity of the solvent has been increased to
form a solid or semi-solid by the addition of appropriate gums,
resins, waxes, polymers, salts, and the like).
Additional Components
A wide variety of additional components can be employed in cosmetic
and personal care compositions according to the present invention.
Examples include the following: hair styling polymers for hair
styling compositions such as hair sprays, gels, and mousses. Hair
styling polymers are well known articles of commerce and many such
polymers are available commercially which contain moieties which
render the polymers cationic, anionic, amphoteric or nonionic in
nature. The polymers may be synthetic or naturally derived.
The amount of the polymer may range from 0.5 to 10%, preferably
0.75 to 6% by weight based on total weight of the composition.
Examples of anionic hair styling polymers are:
copolymers of vinyl acetate and crotonic acid;
terpolymers of vinyl acetate, crotonic acid and a vinyl ester of an
alpha-branched saturated aliphatic monocarboxylic acid such as
vinyl neodecanoate;
copolymers of methyl vinyl ether and maleic anhydride (molar ratio
about 1:1) wherein such copolymers are 50% esterified with a
saturated alcohol containing from 1 to 4 carbon atoms such as
ethanol or butanol;
acrylic copolymers containing acrylic acid or methacrylic acid as
the anionic radical-containing moiety with other monomers such as:
esters of acrylic or methacrylic acid with one or more saturated
alcohols having from 1 to 22 carbon atoms (such as methyl
methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate,
t-butyl acrylate, t-butyl methacrylate, n-butyl methacrylate,
n-hexyl acrylate, n-octyl acrylate, lauryl methacrylate and behenyl
acrylate); glycols having from 1 to 6 carbon atoms (such as
hydroxypropyl methacrylate and hydroxyethyl acrylate); styrene;
vinyl caprolactam; vinyl acetate; acrylamide; alkyl acrylamides and
methacrylamides having 1 to 8 carbon atoms in the alkyl group (such
as methacrylamide, t-butyl acrylamide and n-octyl acrylamide); and
other compatible unsaturated monomers.
The polymer may also contain grafted silicone, such as
polydimethylsiloxane.
Specific examples of suitable anionic hair styling polymers are:
RESYN.RTM. 28-2930 available from National Starch (vinyl
acetate/crotonic acid/vinyl neodecanoate copolymer); ULTRAHOLD.RTM.
8 available from BASF (CTFA designation Acrylates/acrylamide
copolymer); the GANTREZ.RTM.ES series available from ISP
corporation (esterified copolymers of methyl vinyl ether and maleic
anhydride).
Other suitable anionic hair styling polymers include carboxylated
polyurethanes. Carboxylated polyurethane resins are linear,
hydroxyl-terminated copolymers having pendant carboxyl groups. They
may be ethoxylated and/or propoxylated at least at one terminal
end. The carboxyl group can be a carboxylic acid group or an ester
group, wherein the alkyl moiety of the ester group contains one to
three carbon atoms. The carboxylated polyurethane resin can also be
a copolymer of polyvinylpyrrolidone and a polyurethane, having a
CTFA designation PVP/polycarbamyl polyglycol ester. Suitable
carboxylated polyurethane resins are disclosed in EP-A-0619111 and
U.S. Pat. No. 5,000,955. Other suitable hydrophilic polyurethanes
are disclosed in U.S. Pat. Nos. 3,822,238; 4,156,066; 4,156,067;
4,255,550; and 4,743,673.
Amphoteric hair styling polymers which can contain cationic groups
derived from monomers such as t-butyl aminoethyl methacrylate as
well as carboxyl groups derived from monomers such as acrylic acid
or methacrylic acid can also be used in the present invention. One
specific example of an amphoteric hair styling polymer is
Amphomer.RTM. (Octylacrylamide/acrylates/butylaminoethyl
methacrylate copolymer) sold by the National Starch and Chemical
Corporation.
Examples of nonionic hair styling polymers are homopolymers of
N-vinylpyrrolidone and copolymers of N-vinylpyrrolidone with
compatible nonionic monomers such as vinyl acetate. Nonionic
polymers containing N-vinylpyrrolidone in various weight average
molecular weights are available commercially from ISP
Corporation--specific examples of such materials are homopolymers
of N-vinylpyrrolidone having an average molecular weight of about
630,000 sold under the name PVP K-90 and are homopolymers of
N-vinylpyrrolidone having an average molecular weight of about
1,000,000 sold under the name of PVP K-120.
Other suitable nonionic hair styling polymers are cross-linked
silicone resins or gums. Specific examples include rigid silicone
polymers such as those described in EP-A-0240350 and cross-linked
silicone gums such as those described in WO 96/31188.
Examples of cationic hair styling polymers are copolymers of
amino-functional acrylate monomers such as lower alkyl aminoalkyl
acrylate, or methacrylate monomers such as dimethylaminoethyl
methacrylate, with compatible monomers such as N-vinylpyrrolidone,
vinyl caprolactam, alkyl methacrylates (such as methyl methacrylate
and ethyl methacrylate) and alkyl acrylates (such as ethyl acrylate
and n-butyl acrylate).
Specific examples of suitable cationic polymers are:
copolymers of N-vinylpyrrolidone and dimethylaminoethyl
methacrylate, available from ISP Corporation as Copolymer 845,
Copolymer 937 and Copolymer 958;
copolymers of N-vinylpyrrolidone and dimethylaminopropylacrylamide
or methacrylamide, available from ISP Corporation as Styleze.RTM.
CC10;
copolymers of N-vinylpyrrolidine and dimethylaminoethyl
methacrylate;
copolymers of vinylcaprolactam, N-vinylpyrrolidone and
dimethylaminoethylmethacrylate;
Polyquaternium-4 (a copolymer of diallyldimonium chloride and
hydroxyethylcellulose);
Polyquaternium-11 (formed by the reaction of diethyl sulphate and a
copolymer of vinyl pyrrolidone and dimethyl
aminoethylmethacrylate), available from ISP as Gafquat.RTM. 734,
755 and 755N, and from BASF as Luviquat.RTM. PQ11;
Polyquaternium-16 (formed from methylvinylimidazolium chloride and
vinylpyrrolidone), available from BASF as Luviquat.RTM. FC 370, FC
550, FC 905 and HM-552;
Polyquaternium-46 (prepared by the reaction of vinylcaprolactam and
vinylpyrrolidone with methylvinylimidazolium methosulphate),
available from 4L, BASF as Luviquat.RTM.Hold.
Examples of suitable naturally-derived polymers include shellac,
alginates, gelatins, pectins, cellulose derivatives and chitosan or
salts and derivatives thereof. Commercially available examples
include Kytamer.RTM. (ex Amerchol) and Amaze.RTM. (ex National
Starch).
Also suitable for use as optional components in the compositions of
the invention are the ionic copolymers described in WO 93/03703,
the polysiloxane-grafted polymers disclosed in WO 93/23446, the
silicone-containing polycarboxylic acid copolymers described in WO
95/00106 or WO 95/32703, the thermoplastic elastomeric copolymers
described in WO 95/01383, WO 95/06078, WO 95/06079 and WO 95/01384,
the silicone grafted adhesive polymers disclosed in WO 95/04518 or
WO 95/05800, the silicone macro-grafted copolymers taught in WO
96/21417, the silicone macromers of WO 96/32918, the adhesive
polymers of WO 98/48770 or WO 98/48771 or WO 98/48772 or WO
98/48776, the graft polymers of WO 98/51261 and the grafted
copolymers described in WO 98/51755.
With certain of the above-described polymers it may be necessary to
neutralise some acidic groups to promote solubility/dispersibility.
Examples of suitable neutralising agents include
2-amino-2-methyl-1,3-propanediol (AMPD);
2-amino-2-ethyl-1,3-propanediol (AEPD); 2-amino-2-methyl-1-propanol
(AMP); 2-amino-1-butanol (AB); monoethanolamine (MEA);
diethanolamine (DEA); triethanolamine (TEA); monoisopropanolamine
(MIPA); diisopropanol-amine (DIPA); triisopropanolamine (TIPA); and
dimethyl stearamine (DMS). A long chain amine neutralising agent
such as stearamidopropyl dimethylamine or lauramidopropyl
dimethylamine may be employed, as is described in U.S. Pat. No.
4,874,604. Also suitable are inorganic neutralisers, examples of
which include sodium hydroxide, potassium hydroxide and borax.
Mixtures of any of the above neutralising agents may be used.
Amounts of the neutralising agents will range from about 0.001 to
about 10% by weight of the total composition. sunscreening agents
such as 2-ethylhexyl p-methoxycinnamate, 2-ethylhexyl
N,N-dimethyl-p-aminobenzoate, p-aminobenzoic acid,
2-phenylbenzimidazole-5-sulfonic acid, octocrylene, oxybenzone,
homomenthyl salicylate, octyl salicylate,
4,4'-methoxy-t-butyldibenzoylmethane, 4-isopropyl dibenzoylmethane,
3-benzylidene camphor, 3-(4-methylbenzylidene) camphor, titanium
dioxide, zinc oxide, silica, iron oxide, and mixtures thereof.
anti-dandruff actives such as zinc pyrithione, piroctone olamine,
selenium disulphide, sulphur, coal tar, and the like. hair
conditioning agents such as hydrocarbons, silicone fluids, and
cationic materials. The hydrocarbons can be either straight or
branched chain and can contain from about 10 to about 16,
preferably from about 12 to about 16 carbon atoms. Examples of
suitable hydrocarbons are decane, dodecane, tetradecane, tridecane,
and mixtures thereof. Examples of suitable silicone conditioning
agents useful herein can include either cyclic or linear
polydimethylsiloxanes, phenyl and alkyl phenyl silicones, and
silicone copolyols. Cationic conditioning agents useful herein can
include quaternary ammonium salts or the salts of fatty amines.
surfactants for hair shampoo and conditioner compositions. For a
shampoo, the level is preferably from about 10% to about 30%,
preferably from 12% to about 25%, by weight based on total weight
of the composition. For conditioners, the preferred level of
surfactant is from about 0.2% to about 3%, by weight based on total
weight of the composition. Surfactants useful in compositions of
the present invention include anionic, nonionic, cationic,
zwitterionic and amphoteric surfactants. carboxylic acid polymer
thickeners for hair shampoo and conditioner compositions. These
crosslinked polymers contain one or more monomers derived from
acrylic acid, substituted acrylic acids, and salts and esters of
these acrylic acids and the substituted acrylic acids, wherein the
crosslinking agent contains two or more carbon--carbon double bonds
and derived from a polyhydric alcohol. Examples of carboxylic acid
polymer thickeners useful herein are those selected from the group
consisting of carbomers, acrylates/C10-C30 alkyl acrylate
crosspolymers, and mixtures thereof. Compositions of the present
invention can comprise from about 0.025% to about 1%, more
preferably from about 0.05% to about 0.75% and most preferably from
about 0.10% to about 0.50% of the carboxylic acid polymer
thickeners, by weight based on total weight of the composition.
emulsifiers for emulsifying the various carrier components of the
compositions of the invention. Suitable emulsifier types include
polyethylene glycol 20 sorbitan monolaurate (Polysorbate 20),
polyethylene glycol 5 soya sterol, Steareth-20, Ceteareth-20, PPG-2
methyl glucose ether distearate, Ceteth-10, Polysorbate 80, cetyl
phosphate, potassium cetyl phosphate, diethanolamine cetyl
phosphate, Polysorbate 60, glyceryl stearate, PEG-100 stearate, and
mixtures thereof. The emulsifiers can be used individually or as a
mixture of two or more and can comprise from about 0.1% to about
10%, more preferably from about 1% to about 7%, and most preferably
from about 1% to about 5%, by weight based on total weight of the
composition. vitamins and derivatives thereof (e.g., ascorbic acid,
vitamin E, tocopheryl acetate, retinoic acid, retinol, retinoids,
and the like). cationic polymers (e.g., cationic guar gum
derivatives such as guar hydroxypropyltrimonium chloride and
hydroxypropyl guar hydroxypropyltrimonium chloride, available as
the Jaguar.RTM. series from Rhone-Poulenc). preservatives,
antioxidants, chelators and sequestrants; and aesthetic components
such as fragrances, colourings, hair nutrients and essential
oils.
The invention also involves a method of styling hair by applying
thereto a styling composition as is hereinabove described.
The following non-limiting Examples further illustrate the
preferred embodiments of the invention. All percentages referred to
are by weight based on total weight unless otherwise indicated.
EXAMPLES
Synthesis and Characterisation
The synthesis and characterization of the polymers was carried out
according to the following general procedures.
Synthesis
Synthesis of the copolymers of the invention is illustrated by
reference to Example 46 below. Other copolymers of the invention
can be prepared in an analogous manner, as will be evident to those
skilled in the art. 1. bis-initiator ##STR1## 2. free nitroxide
##STR2## 3. monomer for midblock (B block) ##STR3## 4. monomer for
endblock (A block) methyl methacrylate (MMA) and: ##STR4## 5.
Preparation of midblock (B block)
Bis-initiator (0.5557 g, 0.6147 mmol), MEA (40.00 g, 307.36 mmol)
and free nitroxide (2.70 mg, 0.0123 mmol) were mixed in a 200 mL
flask under argon, and heated at 125.degree. C. with vigorous
stirring for 5 hrs, then cooled to room temperature. The conversion
was 77% as measured by .sup.1 H-NMR. The reaction mixture was
dissolved in acetone (60 mL), and precipitated into hexane (600
mL). The polymer was collected and dried under vacuum at 45.degree.
C., affording a clear viscous liquid (30.08 g). 6. Preparation of
triblock copolymer (ABA)
Midblock polymer (28.88 g), diglyme (28.38 g) and free nitroxide
(5.40 mg) were mixed under argon in a glove box to form a
macroinitiator solution. The macroinitiator solution (2.00 g), DMA
(1.198 mL) and MMA (0.821 mL) were mixed in a 15 mL flask under
argon in a glove box and sealed. The solution was stirred and
heated at 125.degree. C. for 8 hrs, then cooled to room
temperature. The mixture was dissolved in acetone (10 mL), and
precipitated by slow addition of hexane (30 mL). The precipitation
process was repeated once. The triblock copolymer was collected and
dried under vacuum overnight, affording a white solid (1.88 g) (the
copolymer of Example 46).
From these polymerisation methods, it will be evident to those of
skill in the art that linking atoms may exist between the A and B
blocks. These linking atoms are typically artefacts of the
particular polymerisation mechanism employed. The presence of the
linking atoms does not necessarily affect the properties of the
block copolymers of the invention and polymers containing linking
atoms are not intended to be excluded from the definition of the
block copolymers no matter which formula is used, such as A-B-A,
A-R-A, etc.
Characterization
Method for Determining Bond Strengths
For an indication of the level of hold offered by a styling polymer
and to assess whether or not it adheres to hair, the bond strength
between the polymer and a single fibre is measured using an
automated bond strength kit. The technique is based on the
principle of using an automated bond strength kit to measure the
force in grams to break a bond between a polymer and two
perpendicularly crossed hair fibres. This was designed by Diastron
Limited (Andover, UK) and is widely used in the hair styling
industry.
Apparatus
Diastron model 600 fitted with Lacquer testing carousel controlled
by Series MTTWin control software (Supplied by Diastron Ltd Andover
UK).
Procedure
a) Preparation of Hair Fibres
Spanish hair (Supplied by Hugo Royer Sandhurst UK) having a maximum
and minimum diameter of between 60 and 80 microns is first cleaned
by submersion in ether for 1 minute. It is then washed with a base
shampoo (16% SLES 2EO) and air dried in a straight conformation at
25 deg C./50%RH for 12 hours.
b) Preparation of Styling Polymer Solution
Make up a 3% concentrated solution of the test styling polymer in a
55% water/45% ethanol mixture.
c) Diastron Control Software Parameters
The values for the test parameters within the MTTWin control panel
(Lacquer Testing Routine) are set as follows:
Percentage Extension % = 100 Rate mm/min = 10 Max Force gmf = 200
Gauge Force gmf = 2 Enable Break detection = 20 Carousel Set Up =
25 samples, Start at 1 (Analysis Break detection = 5)
d) Protocol 1. Mount the cross hair fibres on the aluminium blocks
provided using an alpha cyanoacrylate adhesive (e.g. Cyanolit.TM.).
2. Locate the mounted aluminium blocks in the slots within the
lacquer testing carousel. 3. Using the Diastron crimping apparatus
and mounting block, attach brass ferrule at each end of 25 hair
samples at a spacing of 30 mm as determined by the mounting block.
4. Lay the crimped samples across the mounted hair fibres so that
they lie perpendicularly to each other 5. Cut the crimped hair
fibre using a sharp blade, above the cross-over point with the
horizontal fibre, and at the end nearest to the centre of the
carousel. 6. Using a 1 microliter syringe (Supplied by SGE
International Pty Ltd) deposit 1 microliter of the 3% solids
solution of the test styling polymer into the fibre crossover. 7.
Allow to dry for 3 hours under required temperature and humidity
conditions ie, the conditions under which the bond strength
measurement is to be carried out. 8. Execute the automatic testing
method using the parameters set previously.
e) Data Handling
25 separate load displacement plots are recorded for the carousel
of samples. The peak load supported by the bond is recorded for
each separate test and the mean load and standard deviation
calculated for the carousel.
Size exclusion chromatography (SEC) characterization is performed
in N,N-dimethylformamide (DMF), and molecular weights are
calculated using a calibration obtained with polystyrene standards.
The chain extension of triblock copolymers from midblock polymers
can be clearly observed from SEC data. FIG. 1 shows data from a
representative copolymer after polymerization of the midblock, and
after addition of the endblocks to the midblock. Initially, the
midblock polymer above has a molecular weight of 107,200 g/mol.
After chain extension with DMA, the molecular weight of the
resulting triblock copolymer increases to 161,700 g/mol (relative
to polystyrene standards).
Triblock copolymers are also characterized by .sup.1 H-NMR in
CDCl.sub.3. Signals from different blocks can be clearly seen, and
are consistent with proposed chemical structure of triblock
copolymers. The composition of triblock copolymers (e.g., the molar
ratio of MEA/DMA) may be calculated by comparison of relative
integration of signals from different blocks.
FIG. 2 shows by way of illustration the in-phase (G') and
out-of-phase (G") components of the complex rheological modulus G*
as a function of frequency (.omega.) for a triblock copolymer of
DMA and MEA (different from, but related to, polymers of the
invention). A sample of a DMA-MEA-DMA copolymer with number-average
block molecular weights of 12,000-52,000-12,000 g/mol and a DMA
content of 38 mol % was molded at 120.degree. C. into two disks 12
mm in diameter and 0.8 mm thick. These disks were placed in the
round shear sandwich test fixture of a Rheometric Scientific
DMTA-IV dynamic mechanical thermal analyzer and annealed at
120.degree. C. for 5 minutes prior to measurement. Measurements
were performed at 120.degree. C. with a strain amplitude of 1%. At
high frequencies, the response is dominated by the in-phase or
elastic contribution, as expected. A crossover from in-phase to
out-of-phase behavior is observed around 200 Hz. Viscoelastic
models for polymer behavior generally associate crossovers with the
characteristic time for molecular relaxation mechanisms; crossovers
at such low frequencies are usually associated with motion of
entire molecules. Below this crossover, both G' (.omega.) and G"
(.omega.) scale approximately as .omega..sup.-0.75, in contrast to
the G' (.omega.).about..omega..sup.-2,
G"(.omega.).about..omega..sup.-1 scaling expected for homopolymers.
A second crossover is observed around 0.8 Hz which might be
associated with the motion of molecular aggregates; this second
crossover is generally not seen in homopolymers. The overall shape
of this spectrum resembles that previously observed for other block
copolymers with similar compositions (Zhao, J.; Majumdar, B.;
Schulz, M. F.; Bates, F. S.; Almdal, K.; Mortensen, K.; Hajduk, D.
A.; Gruner, S. M. Macromolecules 1996, 29, 1204-1215; Schulz, M.
F.; Khandpur, A. K.; Bates, F. S.; Almdal, K.; Mortensen, K.;
Hajduk, D. A.; Gruner, S. M. Macromolecules 1996, 29,
2857-2867).
FIG. 3 shows the in-phase (E') and the out-of-phase (E") components
of the complex solid modulus E* for a representative triblock
copolymer of DMA, MEA, and tert-butyl acrylate (tBA) as a function
of temperature at a frequency of 10 Hz, a strain amplitude of 0.1%,
and a heating rate of 2.5.degree. C./min. A DMA-(MEA-co-tBA)-DMA
copolymer with number-average block molecular weights of
14,000-46,000-14,000 g/mol, respectively, a DMA content of 45 mol
%, and a tBA content in the midblock of 10 mol % was molded at
120.degree. C. into a sheet 1.24 mm thick. This sheet was trimmed
into a bar measuring 9.5.times.10 mm and mounted in the single
cantilever test fixture of a Rheometric Scientific DMTA-IV dynamic
mechanical thermal analyzer. The sample was cooled to -50.degree.
C. and permitted to equilibrate for at least five minutes before
the settings of the sample fixture clamps were adjusted to hold the
polymer in place at this temperature. The sample was then returned
to -50.degree. C. and permitted to equilibrate for another five
minutes prior to measurement. The polymer exhibits two glass
transitions, at -15.degree. C. and 45.degree. C., as indicated by
maxima in the curve of E" (T). These values are considerably
different than those measured for pure MEA and DMA (-50.degree. C.
and 100.degree. C., respectively); the discrepancies reflect the
finite heating rate used in this experiment, the presence of 10 mol
% tBA in the MEA block (for which Tg=50.degree. C.), and the mixing
of MEA and DMA across the interfaces separating MEA-rich and
DMA-rich domains.
Method for Determining Elastic Modulus
Modulus (E) was determined at 10 Hz, 1% strain, 25.degree. C. in a
simple tension geometry after two days of equilibration at 50%
relative humidity, 25.degree. C. Samples of polymer were molded at
120.degree. C. into sheets 1.24 mm thick. This sheet was trimmed
into a bar measuring 9.5.times.10 mm and mounted in the single
cantilever test fixture of a Rheometric Scientific DMTA-IV dynamic
mechanical thermal analyzer.
Method for Determining Viscosity
Viscosity (.eta.) was estimated for 5 wt % polymer in 50 vol %
aqueous ethanol solution at 25.degree. C. using capillary
viscometry and assuming a viscosity for deionized water of 1
cp.
Method for Determining Molecular Weights
Number average molecular weights (Mn) for midblock polymers are
calculated from the monomer-to-initiator ratios, and the conversion
of monomer as measured by NMR (generally about 80%), assuming the
polymerization process is living. Mn for endblock polymers are
calculated from DMA mole fractions and Mn values of midblock
polymers. DMA mole fractions are determined by NMR.
Examples 1 to 60
The following are examples of polymers suitable for use in the
present invention.
Polymers containing t-butylacrylate (tBA) All polymers are
DMA-(MEA-co-tBA)-DMA copolymers; (DMA = poly (N,N-
dimethacrylamide)); (MEA-co-tBA) = poly ((2-methoxyethyl)
acrylate-co-tert-butyl acrylate Bond Strength @ 25 C. 5% A sol.
55VOC (g) Polymer Properties Mw A Mw B Total Mw fraction 60% (3%
Flexibility Viscosity Example ABA blocks (kDa) (kDa) (kDa) (%) 30%
50% solids) 80% E (MPa) (mPas) 1 DMA-(MEA-co-tBA) 119 52 290 82
68.5 60.6 5.3 560 11.6 2 DMA-(MEA-co-tBA) 64 52 180 70 539 8.8 3
DMA-(MEA-co-tBA) 57 52 166 67 450 7.9 4 DMA-(MEA-co-tBA) 30 52 112
49 69.5 53.4 3.9 193 5.2 5 DMA-(MEA-co-tBA) 16 52 84 27 <2 4 6
DMA-(MEA-co-tBA) 19 52 90 34 33.9 30.2 0 <2 3.9 7
DMA-(MEA-co-tBA) 23 52 98 40 15 4 8 DMA-(MEA-co-tBA) 27 52 106 45
63 4.6 9 DMA-(MEA-co-tBA) 30 52 112 49 64 53.3 3.7 184 4.4 10
DMA-(MEA-co-tBA) 30 52 112 49 165 4.7 11 DMA-(MEA-co-tBA) 33 52 118
52 115 4.7 12 DMA-(MEA-co-tBA) 36 52 124 54 186 5 13
DMA-(MEA-co-tBA) 49 52 150 63 245 5.9 14 DMA-(MEA-co-tBA) 62 52 176
69 65.2 55.7 3.5 478 6.9 15 DMA-(MEA-co-tBA) 4 28.5 36.5 27 2 5.5
16 DMA-(MEA-co-tBA) 7 28.5 42.5 39 37.8 27.1 0 27 5.5 17
DMA-(MEA-co-tBA) 8 28.5 44.5 42 88 5.9 18 DMA-(MEA-co-tBA) 10.5
28.5 49.5 49 90 7.6 19 DMA-(MEA-co-tBA) 11 28.5 50.5 50 201 8.3 20
DMA-(MEA-co-tBA) 12 28.5 52.5 52 341 6.7 21 DMA-(MEA-co-tBA) 14
28.5 56.5 56 56.2 43.9 2 236 8.8 22 DMA-(MEA-co-tBA) 16 28.5 60.5
60 554 7.5 23 DMA-(MEA-co-tBA) 21 28.5 70.5 66 608 6.8 24
DMA-(MEA-co-tBA) 25.5 28.5 79.5 70 686 6.8 25 DMA-(MEA-co-tBA) 39
28.5 106.5 78 63 59.6 2.3 881 8.6 26 DMA-(MEA-co-tBA) 17.5 52 87 47
67.7 46 33.6 280 (3%) 27 DMA-(MEA-co-tBA) 67 47 181 79 61.7 62.3
54.4 740 (3%) 28 DMA-(MEA-co-tBA) 80 45 80 82 -- -- -- -- 560 11.6
29 DMA-(MEA-co-tBA) 41 46 41 70 -- -- -- -- 539 8.8 30
DMA-(MEA-co-tBA) 36 46 36 67 -- -- -- -- 450 7.9 31
DMA-(MEA-co-tBA) 17 46 17 49 -- -- -- -- 193 5.2 32
DMA-(MEA-co-tBA) 6 46 6 27 -- -- -- -- <2 4.0 33
DMA-(MEA-co-tBA) 9 46 9 34 -- -- -- -- <2 3.9 34
DMA-(MEA-co-tBA) 12 46 12 40 -- -- -- -- 15 4.0 35 DMA-(MEA-co-tBA)
14 46 14 45 -- -- -- -- 63 4.6 36 DMA-(MEA-co-tBA) 17 46 17 49 --
-- -- -- 184 4.4 37 DMA-(MEA-co-tBA) 19 46 19 52 -- -- -- -- 115
4.7 38 DMA-(MEA-co-tBA) 21 46 21 54 -- -- -- -- 186 5.0 39
DMA-(MEA-co-tBA) 30 46 30 63 -- -- -- -- 245 5.9 40
DMA-(MEA-co-tBA) 39 46 39 69 -- -- -- -- 478 6.9
Examples 41 to 48 are (DMA-co-MMA)-MEA-(DMA-co-MMA) copolymers.
Examples 49 to 56 are (DMA-co-MMA)-(MEA-co-nBA)-(DMA-co-MMA)
copolymers. (DMA-co-MMA) = poly (N,N- dimethylamino
acrylamide-co-methyl methacrylate); (MEA-co-nBA) = poly 2-
methoxyethyl) acrylate-co-n-bytyl acrylate). Bond Strength @ 25 C.
55VOC (g) Polymer 40 C. Ex- Properties Mw A Mw B Total A MMA MMA
DMA nBA nBA MEA 60% 60% ample ABA blocks (kDa) (kDa) (kDa) fraction
in A Frac Frac in B Frac Frac 30% 50% (3%) 80% RH 41 (DMA-co-MMA)-
10.5 49 70 0.36 0.13 0.047 0.313 0.640 19.5 25.1 11.1 MEA 42
(DMA-co-MMA)- 16 49 81 0.46 0.13 0.060 0.400 0.540 33.2 19.4 21.2
MEA 43 (DMA-co-MMA)- 32 49 113 0.62 0.13 0.081 0.539 0.380 41 17.2
39.4 MEA 44 (DMA-co-MMA)- 10.5 49 70 0.36 0.48 0.173 0.187 0.640 18
20.1 11.7 MEA 45 (DMA-co-MMA)- 16 49 81 0.46 0.48 0.221 0.239 0.540
36.2 24 25 MEA 46 (DMA-co-MMA)- 25 49 99 0.57 0.48 0.274 0.296
0.430 42.6 35.8 40.2 MEA 47 (DMA-co-MMA)- 54 49 157 0.74 0.12 0.089
0.651 0.260 52.6 12.8 MEA 48 (DMA-co-MMA)- 54 49 157 0.74 0.5 0.370
0.370 0.260 29.5 34.5 MEA 49 (DMA-co-MMA)- 10.7 48 69.4 0.37 0.15
0.056 0.315 0.30 0.189 0.441 21.3 (MEA-co-nBA) 50 (DMA-co-MMA)- 17
48 82 0.48 0.14 0.067 0.413 0.30 0.156 0.364 33.9 (MEA-co-nBA) 51
(DMA-co-MMA)- 31.5 48 111 0.63 0.15 0.095 0.536 0.30 0.111 0.259
43.0 (MEA-co-nBA) 52 (DMA-co-MMA)- 53 48 154 0.74 0.12 0.089 0.651
0.30 0.078 0.182 45.5 14.2 (MEA-co-nBA) 53 (DMA-co-MMA)- 9 48 66
0.33 0.48 0.158 0.172 0.30 0.201 0.469 17.6 (MEA-co-nBA) 54
(DMA-co-MMA)- 14 48 76 0.43 0.49 0.211 0.219 0.30 0.171 0.399 28.0
(MEA-co-nBA) 55 (DMA-co-MMA)- 50 48 148 0.73 0.5 0.365 0.365 0.30
0.081 0.189 36.5 50.8 (MEA-co-nBA) 56 (DMA-co-MMA)- 23.6 48 95.2
0.56 0.5 0.280 0.280 0.30 0.132 0.308 31.9 (MEA-co-nBA)
Examples 57 to 60 are (MMA-co-AA)-MEA-(MMA-co-AA) Copolymers
Polymer Properties Example ABA blocks Mw A Mw B Total Mw A fraction
AA in A MMA Frac MEA Frac AA Fraction 57 (MMA-co-AA)-MEA 11 50 72
0.37 0.22 0.289 0.630 0.081 58 (MMA-co-AA)-MEA 17 50 84 0.49 0.2
0.392 0.510 0.098 59 (MMA-co-AA)-MEA 24 50 98 0.57 0.22 0.455 0.430
0.125 60 (MMA-co-AA)-MEA 49 50 148 0.73 0.22 0.569 0.270 0.161
Comparative Example
The data given above can be compared with that for a block
copolymer in which the core and flanking polymers are derived from
a single monomer.
A DMA-MEA-DMA block copolymer having a molecular weight of 52,000
Da for the DMA blocks and 46,000 Da for the MEA blocks (Comparative
Example) was selected for comparison with the related copolymers of
Example 52. The results are as follows:
Bond Strength (g) at 25.degree. C. Polymer 80% Relative Humidity
Comparative Example 1.5 Example 52 14.2
The use of copolymeric segments in the A or B blocks of an ABA
block copolymer therefore gives surprising advantages in the
resistance to humidity.
Examples 61 to 66
The following are examples of compositions according to the
invention.
The materials used in the examples include the following:
Material Supplier Function Silicone emulsion X2 1787 .TM. Dow
Corning conditioning VOLPO CS 50 .TM. Croda Chemicals surfactant
Sepicide LD .TM. Seppic preservative Cremophor RH410 .TM. BASF
stabiliser Silicone DC 200/DC 24 S .TM. Dow Corning conditioning
Silwet L7602/L-720 .TM. Union Carbide surfactant CAP 40 .TM. Calor
Gas propellant Carbopol 980 .TM. BF Goodrich structurant Jaguar
HP-105 .TM. Rhodia conditioning Silicone Fluid 245 .TM. Dow Corning
conditioning
Ethanol was used as SD Alcohol 40-B (92% active)
Example 61
A styling mousse is formulated as follows:
Material % in product (w/w) Silicone Emulsion X2 1787 1.2 Polymer
of any of Examples 1 1.5 to 60 VOLPO CS 50 0.3 Sepicide LD 0.4
Cremophor RH410 0.2 Ethanol 7.5 CAP 40 8.0 Perfume 0.2 Water to
100%
Example 62
A hairspray is formulated as follows:
Material % in product (w/w) Polymer of any of Examples 1 3.0 to 60
Silicone DC200 0.09 Silwet L7602 0.09 CAP 40 35.0 Ethanol 60.0
Perfume 0.10 Water to 100%
Example 63
A pump spray is formulated as follows:
Material % w/w Ethanol 60.0 Polymer of any of Examples 1 3.5 to 60
Silwet L-720 0.3 Silicone DC24S 0.15 Fragrance 0.3 Water to
100%
Example 64
A styling gel is formulated as follows:
Material % w/w Polymer of any of Examples 1 3.8 to 60 Carbopol 980
0.4 Water to 100% Sepicide LD 0.4 Sodium hydroxide (8% 2 M) 0.1
Ethanol 10.0 Cremaphor RH410 0.4 Jaguar HP-105 0.2 Perfume 0.15
Example 65
A 55% voc propelled aerosol composition is formulated as
follows:
Material % w/w Polymer of any of Examples 1 3.75 to 60 Silicone
Fluid 245 0.20 Fragrance 0.32 Ethanol 19.53 Dimethyl ether 35.00
Sodium benzoate 0.26 Cyclohexylamine 0.21 Water to 100%
Example 66
A 55% voc pump hairspray composition is formulated as follows:
Material % w/w Polymer of any of Examples 1 3.75 to 60
Cyclopentasiloxane (99% 0.15 active) Benzophenone 4 0.0001
Fragrance 0.25 Ethanol 58.00 Water to 100%
* * * * *